The present invention relates to a gear shift mechanism for manually shifting the gears of a transmission system. The shifter is typically used in the automotive field for shifting between the various forward gears and reverse, the shifter being moved in an H or similar pattern depending on the number of forward gears. Movement of the appropriate mechanisms in the transmission is controlled by cables extending between the transmission and the shifter.
With a gear shifter employing the H pattern, for example, it is necessary to convert the two axis motion of the gear shift lever along the legs of the H and across the center bar of the H into substantially parallel motions of the two cables. Prior art shifter constructions for permitting this movement require special configurations of the various parts of the shifter which are somewhat unique for each transmission design. Also, the forming of these component parts requires the use of dedicated tooling to cut and shape and form the geometry of the component by bending and drawing operations. Present constructions also frequently require many welds to hold the component parts together; and modification to design constraints require retooling of the production facility to fabricate the new design.
As one example of the prior art constructions described above, reference is made to U.S. Pat. No. Re. 31,451. The shifter there disclosed includes a complicated array of component parts and a complicated system of multiple pivoting of the different parts of the mechanism to effect parallel movement of the transmission actuation cables. Not only are the individual component parts stamped to unique design configurations, the different parts have to be individually pivotally mounted. In particular, the gear shift lever is attached to a handle bracket which is pivotally mounted in a carrier for movement about one axis. The carrier itself is, in turn, mounted in a support structure for pivoting about a second orthogonal axis. In addition, a separate bell crank member is required and must be mounted for pivoting about a third axis which is canted with respect to the other two axes. A separate drive pin and articulated connection is then required between the carrier and the bell crank in order to complete the shift mechanism.
Other similar constructions for shifting gears are disclosed in U.S. Pat. Nos. 3,808,907 and 4,143,560. As with the construction of the reissue patent, the gear shifting mechanisms of these other patents also require that the gear shift lever be mounted on another member which in turn is pivotally mounted at right angles to the pivoting of the gear shift lever.